Penicillin compounds

ABSTRACT

NOVEL A-HYDROXY-B-PHENOXYETHYL PENICILLINS AND SALTS THEREOF. THE COMPOUNDS POSSESS VALUABLE ANTIBACTERIAL ACTIVITY AND ARE PARTICULARLY USEFUL IN CASES WHERE HYPERSENSITIVITY TO PRESENT-AVAILABLE PENICILLINS MAY OCCUR.

3,699,097 PENICILLIN COMPOUNDS Bernard J. Ludwig, North Brunswick, andFrank M. Berger and George M. Fukui, Princeton, N.J., assignors toCarter-Wallace, Inc., New York, NY. No Drawing. Filed July 19, 1968,Ser. No. 746,004 Int. Cl. C07d 99/16 US. Cl. 260-2391 15 Claims ABSTRACTOF THE DISCLOSURE Novel a-hydroxy-B-phenoxyethyl penicillins and saltsthereof. The compounds possess valuable antibacterial activity and areparticularly useful in cases where hypersensitivity topresently-available penicillins may occur.

United States Patent wherein n is an integer having a value of 0-3 andeach X is chlorine or lower alkyl. As used herein and in the appendedclaims, the term lower alkyl signifies alkyl radicals having from one tosix carbon atoms.

The compounds of the present invention, which can be classified asphenoxylacetamide derivatives of 6-aminopenicillanic acid (6-APA), canbe prepared by the reaction of the proper acylating agent with 6-APA.

Table 1, which follows, sets forth a representative number of thecompounds of the invention. The examples which follow the tableillustrate the preparation of a number of said compounds and saltsthereof as well as the preparation of the lactic acids used asintermediates therein. The numbers used to designate the variouscompounds in the preparative examples and in the further data submittedto demonstrate the utilities thereof correspond to the numbers used inTable I to designate each compound.

TABLE I O-I I CHCOOK Calculated, percent Found, percent No. X M.P.,C.Formula C H N S K 01 C H N S K C 1. H 218-220 C11H21N201SK 46.80 4.866.44 7.35 8.95 46.55 4.72 6.16 7.07 8.76 2 211-212 C11H ClNzO7SK 43.404.26 5.96 6.81 8.30 7.56 43.53 4.21 5.85 6.68 8.51 7.80 222-224C11H2oClNzO1SK 43.40 4.26 5.96 6.81 8.30 7.56 43.67 4.04 6.02 6.83 8.477.73 225-226 C1gHz3N207SK 48.00 5.13 6.22 7.11 8.68 48.66 5.13 6.17 6.958.93 214-216 Cl8H22C1N207SK 44.57 4.36 5.78 6.61 8.06 7.31 44.47 4.235.61 6.40 7.82 7.52 214-216 C1sH2zClN2O1SK 44.57 4.36 5.78 6.61 8.0644.34 4.38 5.43 5.97 7.71 118-145 C11H1aC1 N2O1SK Compound htained inunpurified condition The present invention relates to novel penicillincompounds. More particularly, the invention relates to novel penicillincompounds and their salts which are particularly useful in cases wherehypersensitivity to presently-available penicillins may occur.

' The value of penicillins have been somewhat limited due to the numberof persons which are hypersensitive to the drug and which, uponadministration thereof, develop reactions thereto ranging from milderythema, or hives, to severe serum sickness and, in some cases, toacute anaphylaxis.

It has been estimated that approximately one out of twenty persons arehypersensitive to penicillins, to one degree or another. Consequently, aphysician must use extreme caution in administering the drugs and mustbe prepared to administer resuscitative drugs, such as epinephrine oraminophylline, should a severe reaction develop in the patient.

It is an object of the invention to provide novel penicillin compoundsand salts thereof which have valuable antibacterial action but which, atthe same time, are free from undesirable side reactions. This and otherobjects of the present invention will become apparent to one skilled inthe art in the light of the instant specification.

In its broad aspect, the invention relates to penicillin compoundswhich, in the acid form, have the following general formula:

EXAMPLE 1 Preparation of potassium salt of dl-a-hYdl'OXY-fi-(4-chl010-phenoxy)ethylpenicillin monohydrate (Compound 3) 50 ml. of phosgene,cooled to 60 C., is added to a stirred solution of 44.5 g. ofdl-3-(4-chlorophenoxy)lactic acid in 300 ml. of tetrahydrofuran at roomtemperature. The solution is allowed to stand at room temperature forabout 18 hours and then concentrated under reduced pressure at atemperature not exceeding 40 C. The residue is dissolved in acetone,cooled to 50 C., and a solution of 44.5 g. of 6-aminopenicillanic acidand 52 g. of sodium bicarbonate in water is added with stirring at sucha rate that the temperature does not exceed 20 C. The mixture is stirredfor 2 hours, allowing the temperature to rise to 20 C. It is washed withether and the aqueous layer adjusted to pH 2 with hydrochloric acid. Theacidified mixture is extracted with ether, the ether extract washed withwater, and then extracted with dilute potassium bicarbonate solution,final pH 6.3. The aqueous layer is separated and evaporated to drynessat about 0 C. under reduced pressure. The crude product, weighing aboutg., melts with decomposition at -195 C. It is purified by stirring inrefluxing alcohol, separating by filtration and washing with additionalalcohol and then with acetone. The purified potassium salt ofdl-a-hydroxy-B-(4- chlorophenoxy)ethylpenicillin monohydrate melts withdecomposition at 222-224" C. and has the analytical values summarized inTable I.

3 EXAMPLE 2 Preparation of potassium salt ofdl-a-hydroxy-;8-phenoxyethylpenicillin monohydrate (Compound 1) Theprocedure in Example 1 is foHowed using 8.4 g. of dl-3-phenoxylacticacid and 20 ml. of phosgene. The product is reacted with 10 g. of-aminopenicillanic acid and 12 g. of sodium bicarbonate to obtain about7 g. of crude product. This is purified by digesting with hotisopropanol. Approximately 3 g. of pure potassium salt is obtained,melting withv decomposition at 218-220 C.

EXAMPLE 3 Preparation of potassium salt of dI-a-HYdIOXY-B-(Z- chlro-4,methylphenoxy) ethylpenicillin monohydrate (Compound 6) This compoundis prepared from 23 g. of dl-3-(2- chloro-4-methylphenoxy)lactic acidaccording to the procedure described in Example 1. The reaction product,after washing with hot isopropanol, weighs about 12 g. and melts withdecomposition at 214-216 C.

EXAMPLE 4 The products of thepreceding examples are converted to theirfree-acid forms by neutralization of an aqueous or aqueous alcoholicsolution of their potassium salts with hydrochloric acid to about pH 2.The acids are recovered by extraction into ether or other appropriatewater immiscible organic solvent followed by removal of the solvent.

EXAMPLE 5 The free acids of Example 4 are transformed to their sodium,calcium,. N,N' -dibenzylethylenediamine, and procaine salts byneutralization of a solution thereof with stoichiometric .amount of theappropriate base. The salts are recovered by evaporation of the solventunder reduced pressure at freezing temperatures.

EXAMPLE A Preparation of dl-3-(4-chlorophenoxy)latic acid A mixture of60 g. of dl-chlorolatic acid, 74 g. of pchlorophenol, and 92 g. of 50%solution of sodium hydroxide in 500 ml. of 'Water is heated on asteambath with stirring for 2 hours. The hot mixture is acidified with 130ml. of concentrated hydrochloric acid. After cooling, it is filtered,and the solid washed successively with water, trichloroethylene, andpentane. The crude product (70 g.) is recrystallized from a mixture of200 ml. of methanol and 500 ml. of water withthe aid of charcoal. Thepurified product weighs 44.5 g. and melts at 137-139 C.

Analysis.-Calcd. for C H ClO (percent): C, 49.90; H, 4.19; Cl, 16.37.Found (percent): C, 49.89; H, 4.07; Cl, 16.18. 1

EXAMPLE B Preparation of dI-S-phenoxylatic acid Following the proceduredescribed in Example A, phenol and dl-chlorolatic acid givesdl-3-pheuoxylactic acid which melts at 159161 C.

EXAMPLE C Preparation of dl-3-(2-chloro-4-methylphenoxy) lactic acidFollowing the procedure described in Example A, 2- chloro-4-methylpheno1and dl-chlorolactic acid gives the desired compound. It melts at 99-103C. after being recrystallized once from toluene and twice from water.

Analysis.-Calcd. for C H ClO (percent): C, 52.07; H, 4.81; Cl, 15.36.Found (percent): C, 52.02; H, 4.88; Cl, 15.23.

The activities of the synthetic penicillins of the invention weredetermined by injecting 0.1 ml. of an appropriately diluted Penicillin Gantisera prepared by the method of Levine et al. (J. Exp. Med., 114:888,1961) intradermally on three separate areas on one side of a guinea pig.

The other side of the guinea pig was injected ina similar manner with0.1 ml. of rabbit BSA (bovine serum albumen) anisera in appropriatedilutions (1/500 to 1/2000) and 0.1 ml. of physiological salinesolution.

Four hours later a 1.0-ml. mixture containing 1.0 mg. BSA, 10 mg.Penicillin G (KPG) or a synthetic penicillin compound conjugated to 1mg. of HGG (human gamma globulin) in 0.5% Evans Blue dye solution wasinjected intravenously to each test animal. The KPG or syntheticpenicillin and HGG were incubated together at pH 11.0 for 2 hours at 23C. prior to use to produce the KPG- HGG or synthetic penicillin-HGGconjugate as described by Levine (J. Medicinal Chem, 7:675, 1964).

The test animals received the same amounts of a mixture containing 1.0mg. BSA, 10 mg.'of the benzylpenicilloyl derivative of KPG conjugated to1 mg. of HGG in the manner described above in 0.5% Evans Blue dyesolution. The benzylpenicilloyl derivative of KPG (B'PO) is alleged tobe the major derivative responsible for KPG allergy.

.Fifteen minutes later the reactions at the sites of intradermalinjections were visually observed and scored [passive cutaneousanaphylaxis (PCA) score] as follows, based on the diffusion of the EvansBlue dye around the injection site:

0=No reaction 1+=Very light blue ring, about 2-5mm. in diameter2+==Light blue ring, about 5-10 mm. in diameter 3+=Light blue ring,about 10-15 mm; in diameter 4+=Dark blue ring, about 15-20 mm. indiameter In general, all animals showed no reaction at the site of thesaline injection and substantial reaction at the site of BSA antiserainjection.

The percent reduction of penicillin hypersensitivity for each compoundwas calculated. according to the following formula:

% Reduction of Hypersensitivity T able II, which follows, illustratesthe PCA scores at d1tferent antisera concentrations for an illustrative.compound of the invention and for penicillin.

TABLE II.COMPARATIVE PCA REACTIONS EVOKED BY BPO-HGG, COMPOUND 3-HGG,

CONJUGATED IN GUINEA PIGS SENSITIZED WITH BENICILLIN G ANTISERA PCAreaction at antlsera dilution ol'-- Antl-KPG Guinea Anti-B SA Challengeantigen plg No. 1/50 11150 1/450 1/600 Saline 1 4+ 3+ 2+ 4+ 2 4+ 1+. 4+0 BPO-HGG (10:1) plus 1 mg. BSA 3 4+ 4+ 3+ 4+ 0 4 3+ 1+ 0 4+ 0 5 4+ 3+1+ 4+ 0 6 4+ 2+ 0 4+ 0 P CA scor 23 16 7 24 0 7 1+ 0 0 4+ 0 8 0 v 0 0 4+0 Compound 3-HGG (:1) plus 1 mg. BSA 9 0 0 0 4+ 0 10 0 0 0 4+ 0 l1 0 0 04+ 0 12 2+ 0 0 4+ 0 PCA score 3 0 0 24 0 NQ'rE.Percent reduction(KPG-Ab, 1/50)=233/23X500=87%; Percent reduction (KPG-Ab, 1/150 TAB LEIII Total No. Average of guinea percent pigs tested reduction CompoundNo.2

100=100%; Percent reduction (KPG-Ab, 1/450) =70/7X100=100%; Percentreduction (BSA- The penicillin compounds of the invention were alsoevaluated for their antibiotic eflicacy against Diplococcus pneumoniaeand Streptococcus mastilidis infections in mice by both the oral andintraperitoneal route of administration.

Groups of 20 CF-l mice, weighing approximately 20 grams eachiwereinfected with the organism intraperitoneally. Treatment of the animalsby oral or intraperitoneal routes was initiated 4 hours after infection.One treatment was given on the first day of infection and two treatmentsgiven on each of the second and third days. Treatments were terminatedat the end of the third day.

The cumulated number of surviving animals under various conditions oftreatment is summarized in Tables IVa to IVd, which follow:

TABLE IVa.COMPARATIVE ORAL AND IP IN VIVO ANTIBIOTIC EFFICACY OFCOMPOUND 3-AND KPCi AGAINST DIPLOC'OCCUS PJNEUMOZNLAE INFECTION IN CF-lMICE Treatment 0 Cumulative No. surviving/No. tested (post challenge)at- Dose, Percent Compound Route rug/kg. 1 day 2 days 3 days 6 dayssurvival Untreated 20/20 5/20 2/20 Treatment terminated l/20 6 Oral 0.2ml. 20/20 7/20 20 do v3/ 15 .d0 20/20 20/20 20/20 Compound 3--- ...do-60 20/20 20/20 20/20 100 Control (saline) IP. 0.2 ml. 20/20 15/20 3/2015 G IP 10 a 20/20 20/20 20/20 100 8738 28/38 7 l l0 2 20 20 00 COmPmmd3 20 20 20 20 20 20 20 100 N o'rE.-Cha1lenge dose via IP route:

TABLE IVb.-COMPARATIVE ORAL IN VIVO ANTIBIOTIC EFFICACY OF COMPPNEUMONIAE INFECTION OF CF-l M 300 viable cells; Treatment initiated 4hours after infection.

alpl'aND 3 AND KPG AGAINST DIPLOCOC'CUS Cumulative No. survived/totaltested (post challenge) at- Percent Treatment Dose, mgJkg. 1 day 2 days3 days 4 days 5 days 6 days survival Control Untreated /20 10/20 3/20Treatment terminated.--. 3/20 2/20 1/20 6 0 Saline 3 3/33 2 0 $7 s/g343g 50 0 KG? (Pemclmn G) "i100. 20 20 20 20 20 20 20 20 20 20 100 c d 350.. 20/ 20 20/20 20/ 20 20/20 20/20 100 "{mo 20 20 20 20 20 20 20 20 2020 100 Norm-Challenge dose: 300 viable cells; Therapy initiated 4 hoursafter infection.

TABLE IVc.-COMPARA.TIV E ORAL IN VIVO ANTIBIOTIC EFFICACY F COMPOUND 3AND KPG AGAINST STREPTOCOCC'US MASTITIDIS INFECTION OF CF-l MICECumulative No. survived/total tested (post challenge) at- PercentTreatment Dose, mgJkg. 1 day 2 days 3 days 4 days 5 days 6 days survivalContr0l Untreated 3/20 2/20 1/20 Treatment terminated-.-- 1/20 1/20 1/125 5 3 23533 23758 23538 "'"3 23738 23/33 23/58 138 o.-- KPG (Penicmn 10020 20 20 20 20 20 ...--d6--. 20 20 20 20 20 20 100 0 d3 50 20/20 20/2020/20 20/20 20/20 19/02 v 95 100-.-.- -.20 20 20/20 20 20 20 20 19 20 1920 00 N urn-Chilengedose: 7X cells; Therapy initiated 4 hours afterinfection.

TABLE Nil-COMPARATIVE ORAL IN VIVO ANTIBIOTIO EFFICACY 0F COMPOUND 3 ANDKPG AGAINST STREPTOC'OOCUSMASTITIDIS INFECTION OF CF-l MICE 1 6Cumulative N0. surviving/total tested post challenge at- Dose/treatment,Percent Treatment mgJkg. lday 'Zdays 3days 4days fidays survival ControlUntreated- 3/20 2/ 2/20 Treatment terruinated; 1/20 0/20 0 D0 292s .922.999 .999 0 ""'09---- 22/99 i929 i993 0 929 922 929 1/99 a--'----i100IIIIIIII 3/20 1 20 1/20 1 20 6 Norm-Challenge dose: 1.1X10cells; Therapy initiated 4 hours aiter infection.

The pcncillin compounds of this invention are preferably administeredorally in the form of tablets, capsules, or the like. The compounds mayalso be administered by injection using a suspension of the compound inwater or isotonic saline solution or a solution of the compound in asolvent consisting of aqueous propylene glycolor polyethylene glycol. Inaddition to the active ingredient, the tablet contains conventionalfillers, excipients, lubricants, etc. The active compound is generallyin an amount from 25 to 90% by weight of the total composition. Typicalexamples of such tablets or capsules are those containing the penicillinactive ingredient in an amount of from 100 to 1000 mg., preferably 500mg.

What is claimed is:

1. A compound selected from the group consisting of 3. A nontoxicpharmaceutically-acceptable salt of the 50 compound of claim 2. r

4. d1 a Hydroxy-p-(2-chlorophenoxy)ethylpenicillin.

monohydrate.

5. A nontoxic pharmaceutically-acceptable salt of the;

compound of claim 4.=

'6. dl-a-Hydroxy B (4-chlorophen'oxy)ethylpenicillin monohydrate. p

A nontoxic pharmaceutically-acceptable salt of in; 25 compound of claim6. 8. d1 0c Hydroxy-fl-(Z-methylphenoxy ethylpenicillin M monohydrate.

9. A nontoxic pharmaceutically-acceptable salt of the compound of claim8.

10. d1 a Hydroxy-,8-(Z-methyl-4 chlorophenoxy) w ethylpenicillinmonohydrate.

11. A nontoxic pharmaceutically-acceptable salt of the compound of claim10.

12. d1 a Hydroxy- 3-(2-chloro-4-methylphenoxy)ethylpenicillinmonohydrate.

13. A nontoxic pharmaceuticallyacceptable salt of the compound of claim12.

14. dl c: Hydroxy-fl-(2,4,6-trichlorophenoxy)ethylnicillin monohydrate.

15. A nontoxic pharmaceutically-acceptable salt of the compound of claim14.

v References Cited UNITED STATES PATENTS 3,316,248 4/1967 Cheney260239.1 3,352,852 11/1967 Cheney 260-239.l 3,116,285 12/1963 Celmer eta1. 260-239.l

, FOREIGNPATENTS v 1-737.467 6/1966 Canada 260-2301 080,042 10/1961Great Britain 260-239.1

NICHOLAS s. RIZZO. Primary Examiner US. Cl. X. R.

